EXTREMELY SIMPLE DIY GEIGER COUNTER - Built it dirt cheap (nearly all vendors are sold out and back ordered for months)

Face it, buying a Geiger Counter right now and you will have to wait for months....or pay out your life savings to buy one on Ebay IF they are available.

Luckily you can still obtain the parts to make a simple Geiger Counter that works well enough to let you know when radiation is in your area.

MATERIALS NEEDED:
-Digital Voltmeter
-9v Battery or any battery within the 1-9v range
-Transistor of the ordinary NPN Darlington type MPSAW45A
-Metal Can soup can or any metallic can
-Some insulated wire
-Wire splice/cutter or razor blades (be creative in a pinch)
-Electrical tape (or be creative in a pinch)
-Small sheet of Aluminum Foil

:geigercircuit01:

ION CHAMBER: Don't let the name intimidate you, it is very simple. Like a 3rd grade science project.

We need a wire to run through the center axis of the metal can. The center lead wire CAN NOT conduct into the metal can, keep it insulated from each other. Be clean and detail oriented as little things like wire straightness can adjust reading sensitivity.

One side of the can is cut open (can opener like is fine) and the other end is sealed.
Run one end of the lead wire out of the can (open side) and keep insulated outside the can but leave a contact point at the end.

Soder, bolt or secure some how a wire from the metal can and extend off the can insulated like the lead wire. Now we have the two terminals for the Ion Chamber. Almost done.
Next we cover the cans open side with aluminum foil (don't ground out the center lead wire). Be sure to cover well as to greatly reduce airflow in the can. This is the "screen" where the radiation will enter the Ion Chamber.

Once that is completed, wire up the remaining circuit. The transistor can be bought at most Radio Shacks or other Store which sells circuitry components.

:simplegeigerpic0:

This is about as simple as it can get. The Digital Voltmeter should be set to mV (millivolts).

Highly advisable to build it before radiation floods in so you have a back ground radiation measurement.

If the Voltmeter isn't reading then let the unit sit, powered on, for 20 minutes then check again.